Mobile communications networks include a plurality of base stations, each of which is in communication with an antenna. The base stations have traditionally been located close to their respective antennas. When located in close proximity, many parallel connections are used to couple a modem of the base station to a transceiver near the antenna. When the modem and the transceiver are at the same location, this is not overly burdensome.
Some systems utilize an architecture where a Transceiver and Power Amplifier (“PA”) is located far away from its associated base station, possibly up to several kilometers. This potentially allows a single base station to drive several Transceiver-PA sites, saving the system operator money in terms of a base station investment as well as floor space.
Many networks utilize the Universal Mobile Telecommunications System (“UMTS”) technology (one of the third-generation (“3G”) mobile phone technologies), to transmit data between a base station having a modem and its respective remotely-located transceiver. The UMTS technology is commonly used in Europe.
A competing technology for transmitting data between a base station's modem and its transceiver is Code Division Multiple Access-2000 (“CDMA-2000”). CDMA-2000 is a 3G mobile telecommunications standard that uses CDMA, a multiple access scheme for digital radio, to send voice, data, and signaling data (such as a dialed telephone number) between the base stations' modems and their respective transceivers and between mobile telephones and cell sites. CDMA-2000 is often used in the U.S. and in Asia. However, CDMA-2000 is an incompatible competitor of UMTS.
Currently, a base station communicates data with its transceiver and RF antenna via a series of many parallel copper connections. When the modem and the transceiver are at the same location, this is not overly burdensome. However, when the modem and the transceiver are located apart by several kilometers, it is not practical to use such copper interconnect to couple the modem to the transceiver.
Common Public Radio Interface (“CPRI”) is an interface that has been designed to transport UMTS data over a link between, e.g., a base station's modem and its remotely-located transceiver. CPRI has been utilized to transport UMTS data between a base station's modem and its remotely located transceiver when the base station's modem and the remotely located transceiver are separated by, e.g., a kilometer or more. CPRI allows use of a small cable to transfer control communication and baseband data between the modem and the transceiver. CPRI provides a high data rate over far fewer wires than would be possible with the use of a non-CPRI interface. However, no such architecture has been developed for carrying CDMA baseband data over a CPRI interface.
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